"The objective of this analysis was to prospectively determine the effects of nutrient intakes on the incidences of preeclampsia and pregnancy-associated hypertension among women enrolled in the Calcium for Preeclampsia Prevention study... After adjustment for baseline risks, none of the 28 nutritional factors analyzed were significantly related to either preeclampsia or pregnancy-associated hypertension."

Jamie, there's no evidence that calcium harms. :-) There is that evidence in the antioxidant case, but I can completely see why someone would scrip CA just in case dietary intake put someone more into the category of the sampled Third-World population who had lower eclampsia rates if they were supplemented.

Vitamin D is still in massive studies. As I understand it there's some link between autoimmune conditions and low serum D, so we might just be picking out the population of women who are autoimmune. It has something to do with genetically variant receptors. (I know there have been a number of posters here who've had low D and needed really serious supplementation to raise their levels, and IIRC psoriasis patients are often just unresponsive to dietary supplementation of D and can only get more sun.)

It didn't do anything to the Standard-American-Diet population in Chicago, IIRC -- I'll try to find the study.

They have hesitated to run with the "can't hurt might help" line of thinking after the bigger antioxidant trials started to come out. There's a plausible mechanism for action of antioxidants to prolong pregnancy, and while they were in trials everyone pretty much said, well goodness, vitamins C and E can't *hurt* you so go ahead and take them.

Then the study data showed that women supplementing antioxidants, while they didn't develop preeclampsia at higher rates, got sicker quicker, with earlier onset of preeclampsia and more severe cases.

And that made everyone say, wow. This is far more unintuitive than we thought. We had better stop saying, well it can't hurt, because we don't actually know.

I've seen two different MFM equivalents in the UK - one of whom recommended calcium and one didn't.

I find it curious as to why its not recommended on the basis of the larger trial, because even if it doesn't change the primary outcome, pre-eclampsia rates, those secondary outcomes look really important to me. I mean, reducing severity, maternal morbidity, and neonatal mortality look like outcomes well worth having, don't they? Or did it not do anything in populations with higher dietary calcium intakes? What about women who don't eat diary products like me, I might well have a low calcium intake. Admittedly I've not read the papers.

That's the Cochrane Review, but that's a meta-analysis of a bunch of smaller studies.

Since then a much larger study has come out: Randomized placebo-controlled, double-blinded trial in nulliparous normotensive women from populations with dietary calcium < 600 mg/d... A 1.5-g calcium/day supplement did not prevent preeclampsia but did reduce its severity, maternal morbidity, and neonatal mortality, albeit these were secondary outcomes.

So basically in populations with really poor calcium intake it seems to reduce rates of eclampsia and severe hypertension, but preeclampsia rates didn't budge.

Here's current recs: Supplementation with fish oil, calcium, or vitamin C and E and the use of antihypertensives have been shown to be ineffective in the prevention of recurrent preeclampsia and are not recommended. Supplementation with low-dose aspirin may be offered on an individualized basis.